An isometric adaptive variable stiffness vibration damping device

Abstract

The utility model relates to the technical field of damping, specifically relates to a equal -length adaptive variable stiffness damping device, including spacing assembly and by spacing assembly restriction moves first board, second board, third board and fourth board, the first board is connected through the upper spring between second board, third board and fourth board are connected through the lower spring, the first board is fixed with a steel pipe in vertical direction, is located in the steel pipe and is opened in the third board vertical fixed one pull rod, the pull rod is opened and has the fixed hole matching with the spacing hole, the utility model discloses can change the rigidity of device automatically when the structure vibration amplitude is bigger, thereby effectively avoid resonance, solve the structural resonance problem caused by the diversity of external excitation frequency, and the working length of the device is kept unchanged, when the civil structure applies the device as the pull rod / cable, can greatly reduce the influence of vibration on civil structure.

Description

Technical Field

[0001] This utility model relates to the field of vibration reduction technology, specifically to an equal-length adaptive variable stiffness vibration reduction device. Background Technology

[0002] Civil engineering structures, such as cable-stayed pedestrian bridges, will vibrate under external excitations such as pedestrian loads, wind loads, and seismic forces. When the frequency of the external excitation is close to the natural frequency of the structure, resonance is easily triggered, leading to a significant amplification of the structural vibration response.

[0003] External excitation frequencies vary due to differences and uncertainties in the vibration source. Once an existing structure is built, its natural frequency is basically fixed and difficult to adjust according to changes in the external excitation frequency, thus posing a risk of resonance under specific excitations.

[0004] Some existing vibration damping devices attempt to adjust the dynamic characteristics of a structure by changing its stiffness. However, in most cases, the device length also changes along with the stiffness, affecting the structural state and limiting its application. Therefore, how to achieve adaptive stiffness adjustment while keeping the device length constant to reduce the vibration response of the structure under various excitations remains a technical problem to be solved. Utility Model Content

[0005] The purpose of this invention is to provide an adaptive variable stiffness vibration reduction device.

[0006] This utility model provides the following technical solution:

[0007] This utility model proposes an equal-length adaptive variable stiffness vibration reduction device, including a limiting component and a first plate, a second plate, a third plate and a fourth plate whose movement is limited by the limiting component;

[0008] The first plate and the second plate are connected by an upper spring; the third plate and the fourth plate are connected by a lower spring.

[0009] A steel pipe is vertically fixed under the first plate, and a limiting hole is provided on the steel pipe;

[0010] A tie rod located inside the steel pipe is vertically fixed on the third plate, and a fixing hole matching the limiting hole is provided on the tie rod;

[0011] The limiting component includes a connecting rod hinged to the outer wall of the steel pipe, and a locking pin inserted into the limiting hole is provided at the upper end of the connecting rod; a return spring is provided laterally on the outer wall of the steel pipe, and the return spring contacts the lower part of the connecting rod. When the fixing hole is flush with the limiting hole, the return spring drives the connecting rod to drive the locking pin to be inserted into the fixing hole.

[0012] Below the connecting rod is a mass block for driving the upper end of the connecting rod to move outward; a vibration amplification spring is also fixed on the outer wall of the steel pipe, and the upper end of the vibration amplification spring is fixedly connected to the mass block.

[0013] A first steel cable, used to limit the distance between the first plate and the third plate, runs longitudinally through them.

[0014] A second steel cable runs longitudinally between the second plate and the fourth plate to limit the distance between them.

[0015] Furthermore, the limiting component includes two pairs of steel cables: one pair each for the first steel cable and the second steel cable; both the upper and lower ends of the steel cables are equipped with anchor heads.

[0016] The upper end of the first steel cable passes through the left and right sides of the first plate, and the lower end of the first steel cable passes through the left and right sides of the second plate and the third plate;

[0017] The upper end of the second steel cable passes through the left and right sides of the second plate, and the lower end of the second steel cable passes through the left and right sides of the third plate and the fourth plate.

[0018] Furthermore, the distance between the first plate and the second plate is the same as the distance between the third plate and the fourth plate; the first steel cable and the second steel cable have the same length; and the upper spring and the lower spring have the same stiffness coefficient.

[0019] Furthermore, a support plate is horizontally fixed to the outer wall of the end of the steel pipe, and a first spring guide rod is vertically fixed to the support plate. The vibration amplification spring is sleeved on the first spring guide rod, and the height of the vibration amplification spring is greater than the height of the first spring guide rod. The end of the vibration amplification spring is fixed to the support plate.

[0020] Furthermore, a support rod is fixed to the outer wall of the steel pipe, and the connecting rod is hinged to the support rod.

[0021] Furthermore, a second spring guide rod is horizontally fixed to the outer wall of the steel pipe, and the return spring is sleeved on the second spring guide rod. The length of the return spring is greater than the length of the second spring guide rod, and the end of the return spring is fixed to the outer wall of the steel pipe.

[0022] Furthermore, a swing hole is provided at the tail end of the locking pin, and the upper end of the connecting rod passes through the swing hole.

[0023] Furthermore, the upper surface of the first plate has an upper pull ring; the lower surface of the fourth plate has a lower pull ring.

[0024] Compared with the prior art, this utility model can automatically change the stiffness of the device when the structural vibration amplitude is large, thereby effectively avoiding resonance and solving the structural resonance problem caused by the diversity of external excitation frequencies. At the same time, the working length of the device remains unchanged. When this device is used as a tie rod / cable in civil structures, the impact of vibration on the civil structure can be greatly reduced. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this device.

[0026] Figure 2 This is a schematic diagram of the enlarged structure of A.

[0027] Figure 3 for Figure 1 A schematic diagram of the force transmission path under the specified conditions.

[0028] Figure 4 This is a schematic diagram of the device when the locking pin is pulled out of the fixing hole.

[0029] Figure 5 This is a schematic diagram of the enlarged structure of B.

[0030] Figure 6 This is a schematic diagram of the structure of the device when the third and fourth plates reach the anchor heads at the ends of the first and second steel cables, respectively.

[0031] Figure 7 for Figure 6 In this state, a schematic diagram of the force transmission path of the upper pull ring, the first steel cable, the lower spring, and the lower pull ring is shown.

[0032] Figure 8 for Figure 6 The diagram shows the force transmission path of the upper pull ring, upper spring, second steel cable, and lower pull ring in the current state.

[0033] Figure 9 This is a schematic diagram of replacing a section of a tensioned rod / cable with the cost device.

[0034] Figure 10 This is a structural diagram of a device for replacing the entire tensioned rod / cable.

[0035] The arrows represent the direction of force transmission.

[0036] In the diagram, 11-first plate; 12-second plate; 13-third plate; 14-fourth plate; 21-upper pull ring; 22-lower pull ring; 23-upper spring; 24-lower spring; 31-steel pipe; 32-support rod; 33-connecting rod; 34-locking pin; 35-reset spring; 36-second spring guide rod; 37-swing hole; 41-support plate; 42-vibration amplification spring; 43-first spring guide rod; 44-mass block; 51-pull rod; 52-fixing hole; 61-first steel cable; 62-second steel cable; 71-anchor head. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings.

[0038] See Figure 1 , Figure 2 and Figure 5 In one embodiment, an equal-length adaptive variable stiffness vibration damping device includes a limiting component and a first plate 11, a second plate 12, a third plate 13 and a fourth plate 14 whose movement is limited by the limiting component.

[0039] The first plate 11 and the second plate 12 are connected by an upper spring 23; the third plate 13 and the fourth plate 14 are connected by a lower spring 24.

[0040] A steel pipe 31 is vertically fixed below the first plate 11, and a limiting hole is provided on the steel pipe 31;

[0041] A tie rod 51 located inside the steel pipe 31 is vertically fixed on the third plate 13. The tie rod 51 has a fixing hole 52 that matches the limiting hole.

[0042] The limiting assembly includes a connecting rod 33 hinged to the outer wall of the steel pipe 31, and a locking pin 34 inserted into the limiting hole is provided at the upper end of the connecting rod 33. A return spring 35 is provided laterally on the outer wall of the steel pipe 31, and the extension end of the return spring 35 contacts the lower part of the connecting rod 33. When the fixing hole 52 is flush with the limiting hole, the compressed return spring 35 drives the connecting rod 33 to drive the locking pin 34 to insert into the fixing hole 52.

[0043] Below the connecting rod 33 is a mass block 44 for driving the upper end of the connecting rod 33 to move outward; a vibration amplification spring 42 is also fixed on the outer wall of the steel pipe 31, and the upper end of the vibration amplification spring 42 is fixedly connected to the mass block 44.

[0044] A first steel cable 61, used to limit the distance between the first plate 11 and the third plate 13, runs longitudinally through them.

[0045] A second steel cable 62, used to limit the distance between the second plate 12 and the fourth plate 14, runs longitudinally through them.

[0046] By adopting the above technical solution, when external excitations such as crowd loads and wind loads occur, the mass block 44 vibrates up and down under the action of the vibration amplification spring 42. The natural frequency of the combination of the mass block 44 and the vibration amplification spring 42 is... Figure 1 The natural frequencies of the structure are consistent under the condition ( Figure 1 The force transmission path in the state is as follows Figure 3 As shown, if the stiffness of both the upper spring 23 and the lower spring 24 is K, then Figure 1 The device stiffness in this state is K / 2. If the excitation frequency is close to the structural vibration frequency, resonance occurs, and the vibration amplification spring 42 amplifies the amplitude of the mass block 44. When the amplitude of the mass block 44 exceeds the set threshold, it strikes the connecting rod 33, causing the connecting rod 33 to rotate. The lower part of the connecting rod 33 compresses the return spring 35, and the upper end of the connecting rod 33 moves outward and drives the locking pin 34 to be pulled out of the fixing hole 52. Figure 4 Or as shown in Figure 5.

[0047] After the locking pin 34 is pulled out of the fixing hole 52, the pull rod 51 will move downwards, and the third plate 13 and the fourth plate 14 will move downwards, eventually reaching the ends of the first steel cable 61 and the second steel cable 62. The first steel cable 61 and the second steel cable 62 will be stretched and thus function. Figure 6 As shown, at this point, there are two force transmission paths, as follows: Figure 7 and Figure 8 As shown, there is no force between the steel pipe 31 and the tie rod 51. (If the stiffness of the upper spring 23 and the lower spring 24 are both K, then...) Figure 6 The device stiffness in the state is 2K. The natural frequency of the device changes, which avoids resonance, reduces the vibration amplitude, and achieves a vibration reduction effect.

[0048] When the excitation frequency is Figure 6 When the natural frequencies of the structure are close in the state, causing a large amplitude of motion, when the fixing hole 52 reaches the limiting hole of the steel pipe 31, the elastic potential of the compressed return spring 35 pushes the lower part of the connecting rod 33 outward, and the upper end of the connecting rod 33 moves inward, driving the locking pin 34 to insert into the fixing hole 52, thereby restoring the device to its original state. Figure 1 In this state, the device's natural frequency changes again, avoiding resonance and achieving adaptive variable stiffness vibration reduction.

[0049] See Figure 1 In one embodiment, the limiting component includes two pairs of steel cables: a pair of first steel cables 61 and a pair of second steel cables 62 are provided; both the upper and lower ends of the steel cables (61 and 62) are provided with anchor heads 71;

[0050] The upper end of the first steel cable 61 passes through the left and right sides of the first plate 11, and the lower end of the first steel cable 61 passes through the left and right sides of the second plate 12 and the third plate 13.

[0051] The upper end of the second steel cable 62 passes through the left and right sides of the second plate 12, and the lower end of the second steel cable 62 passes through the left and right sides of the third plate 13 and the fourth plate 14.

[0052] That is: one of the first steel cables passes through the left side of the first plate 11, the left side of the second plate 12, and the left side of the third plate 13 from top to bottom; the other cable passes through the right side of the first plate 11, the right side of the second plate 12, and the right side of the third plate 13 from top to bottom.

[0053] One of the second steel cables passes through the left side of the second plate 12, the left side of the third plate 13, and the left side of the fourth plate 14 from top to bottom; the other cable passes through the right side of the second plate 12, the right side of the third plate 13, and the right side of the fourth plate 14 from top to bottom.

[0054] In the above technical solution, after the locking pin 34 is pulled out of the fixing hole 52, the pull rod 51 will move downwards, the third plate 13 and the fourth plate 14 will move downwards, and finally reach the anchor head of the first steel cable 61 and the second steel cable 62, restraining the third plate and the fourth plate to move further away.

[0055] See Figure 3 In one embodiment, the distance between the first plate 11 and the second plate 12 is the same as the distance between the third plate 13 and the fourth plate 14, both being L1; the lengths of the first steel cable 61 and the second steel cable 62 are the same, both being L3; the stiffness coefficients of the upper spring 23 and the lower spring 24 are the same, both being K. Figure 1 The distance L2 between the second and third plates in the state; L3-L1-L2=3F / 2K; so that the length of the device remains unchanged before and after the stiffness change.

[0056] In the above technical solution, the distance between the first plate 11 and the second plate 12 is L1, and the distance between the third plate 13 and the fourth plate 14 is L2. Figure 1 The distance between the second plate 12 and the third plate 13 in the current state is L2, and the lengths of the first steel cable 61 and the second steel cable 62 are both L3. Figure 1 The initial length of the device is

[0057] 2L1+L2 (1)

[0058] Under the tension force F Figure 1 The length of the device after deformation is:

[0059] L s =2L1+L2+2F / K (2)

[0060] Under the tension force F, Figure 6 The length of the device after deformation is:

[0061] L p =L3+L1+F / 2K (3)

[0062] If the length of the device remains constant before and after the change in stiffness, then:

[0063] L s =L p (4)

[0064] Right now:

[0065]

[0066] See Figure 1 and Figure 2 In one embodiment, a support plate 41 is horizontally fixed to the outer wall of the end of the steel pipe 31, and a first spring guide rod is vertically fixed on the support plate 41. The vibration amplifying spring 42 is sleeved on the first spring guide rod 43, and the height of the vibration amplifying spring 42 is greater than the height of the first spring guide rod 43. The end of the vibration amplifying spring 42 is fixed on the support plate 41. This allows the vibration amplifying spring 42 to move vertically, preventing it from tilting and falling down, while ensuring that the vibration amplifying spring 42 can be compressed and extended.

[0067] Please continue reading. Figure 1 and Figure 2 In one embodiment, a support rod 32 is fixed to the outer wall of the steel pipe 31, and the connecting rod 33 is hinged to the support rod 32; providing a support point for the swing of the connecting rod 33.

[0068] Please continue reading. Figure 1 and Figure 2 In one embodiment, a second spring guide rod 36 is horizontally fixed to the outer wall of the steel pipe 31, and a reset spring 35 is sleeved on the second spring guide rod 36. The length of the reset spring 35 is greater than the length of the second spring guide rod 36, and the end of the reset spring 35 is fixed to the outer wall of the steel pipe 31. This prevents the reset spring 35 from tilting and falling down, while ensuring that the reset spring 35 can be compressed and reset.

[0069] See Figure 4 and Figure 5 In one embodiment, a swing hole 37 is provided at the tail end of the locking pin 34, and the upper end of the connecting rod 33 passes through the swing hole 37; by providing the swing hole 37, the upper end of the connecting rod 33 can drive the locking pin 34 to move inward and outward.

[0070] In one embodiment, the upper end of the connecting rod 33 is hinged to the end of the locking pin 34 (a conventional solution that can replace the above-mentioned swing hole, which is not shown and will not be described in detail); the hinge can also enable the upper end of the connecting rod 33 to drive the locking pin 34 to move inward and outward.

[0071] See Figure 1 In one embodiment, the upper surface of the first plate 11 has an upper pull ring 21; the lower surface of the fourth plate 14 has a lower pull ring 22; to facilitate connection with external components.

[0072] In tension members of civil structures, such as the cables of a cable-stayed pedestrian bridge or the cables of a tensioned beam structure, the stiffness is constant. In practical applications, this device can be used to replace a section or the entire section of a tensioned rod / cable. Figure 9 and Figure 10 As shown, the stiffness of tension members can be adjusted to prevent structural resonance.

[0073] The tensile force F is the tensile force required to connect component A and component B. The tensile force is F both when using this device and when not using it. This device does not change the stress performance of the structure under static conditions. Furthermore, the static length remains unchanged before and after the device changes stiffness, and the boundary conditions of the structure are not altered.

[0074] Working principle: This device is in Figure 1 In this state, the locking pin 34 passes through the fixing hole 52, and the pull rod 51 and the steel pipe 31 are securely connected. The upper spring 23, the steel pipe 31, the pull rod 51, and the lower spring 24 form a series system, and the force transmission path is as follows: Figure 3 As shown, if the stiffness of both the upper spring 23 and the lower spring 24 is K, then the system stiffness is K / 2.

[0075] When subjected to external vibration, the mass block 44 will vibrate up and down under the action of the vibration amplification spring 42. The natural frequency of the combination of the mass block 44 and the vibration amplification spring 42 is consistent with the natural frequency of the structure with a system stiffness of K / 2. The vibration amplification spring 42 will amplify the amplitude of the mass block 44. When the amplitude of the mass block 44 exceeds the set threshold, it will strike the connecting rod 33, causing the connecting rod 33 to rotate. The lower part of the connecting rod 33 will compress the return spring 35, and the upper end of the connecting rod 33 will move outward and drive the locking pin 34 to pull out of the fixing hole 52. Figure 4 Or as shown in Figure 5.

[0076] Under the action of tension, the tie rod 51 will move downwards, and the third plate 13 and the fourth plate 14 will eventually reach the anchor head 71 of the first steel cable 61 and the second steel cable 62, as shown. Figure 6 As shown, at this time, there is no force between the steel pipe 31 and the pull rod 51, and there are two force transmission paths: the upper pull ring 21, the first steel cable 61, the lower spring 24, and the lower pull ring 22. The force transmission paths are as follows: Figure 7As shown; upper pull ring 21, upper spring 23, second steel cable 62, lower pull ring 22, the force transmission path is as follows: Figure 8 As shown. At this time, the upper spring 23 and the lower spring 24 are connected in parallel, the system stiffness is 2K, the natural frequency of the system changes, resonance is avoided, the vibration amplitude is reduced, and the vibration reduction effect is achieved.

[0077] In the 2K stiffness state, if the excitation frequency is close to the natural frequency of the structure in the 2K state, it will cause relative movement between the second plate 12 and the third plate 13. When the amplitude of movement is large, and the fixing hole is aligned with the limiting hole, the elastic potential of the compressed return spring 35 will push the lower part of the connecting rod 33 outward, and the upper end of the connecting rod 33 will move inward and drive the locking pin 34 to insert into the fixing hole 52, thereby restoring the device to its original position. Figure 1 In this state, the device's natural frequency changes again, avoiding resonance and achieving adaptive variable stiffness vibration reduction.

[0078] The embodiments of this utility model are given for the purpose of illustration and description. Although embodiments of this utility model have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this utility model. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this utility model.

Claims

1. A constant-length adaptive variable stiffness vibration damping device, characterized in that: Includes a limiting component and a first plate, a second plate, a third plate, and a fourth plate whose movement is limited by the limiting component; The first plate and the second plate are connected by an upper spring; the third plate and the fourth plate are connected by a lower spring. A steel pipe is vertically fixed under the first plate, and a limiting hole is provided on the steel pipe; A tie rod located inside the steel pipe is vertically fixed on the third plate, and a fixing hole matching the limiting hole is provided on the tie rod; The limiting component includes a connecting rod hinged to the outer wall of the steel pipe, and a locking pin inserted into the limiting hole is provided at the upper end of the connecting rod; a return spring is provided laterally on the outer wall of the steel pipe, and the return spring contacts the lower part of the connecting rod. When the fixing hole is flush with the limiting hole, the return spring drives the connecting rod to drive the locking pin to be inserted into the fixing hole. Below the connecting rod is a mass block for driving the upper end of the connecting rod to move outward; a vibration amplification spring is also fixed on the outer wall of the steel pipe, and the upper end of the vibration amplification spring is fixedly connected to the mass block. A first steel cable, used to limit the distance between the first plate and the third plate, runs longitudinally through them. A second steel cable runs longitudinally between the second plate and the fourth plate to limit the distance between them.

2. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: The limiting component includes two pairs of steel cables: one pair each for the first steel cable and the second steel cable; both the upper and lower ends of the steel cables are equipped with anchor heads. The upper end of the first steel cable passes through the left and right sides of the first plate, and the lower end of the first steel cable passes through the left and right sides of the second plate and the third plate; The upper end of the second steel cable passes through the left and right sides of the second plate, and the lower end of the second steel cable passes through the left and right sides of the third plate and the fourth plate.

3. The equal-length adaptive variable stiffness vibration damping device according to claim 2, characterized in that: The distance between the first plate and the second plate is the same as the distance between the third plate and the fourth plate; the first steel cable and the second steel cable have the same length; the upper spring and the lower spring have the same stiffness coefficient.

4. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: A support plate is horizontally fixed to the outer wall of the end of the steel pipe, and a first spring guide rod is vertically fixed to the support plate. The vibration amplification spring is sleeved on the first spring guide rod, and the height of the vibration amplification spring is greater than the height of the first spring guide rod. The end of the vibration amplification spring is fixed to the support plate.

5. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: A support rod is fixed to the outer wall of the steel pipe, and the connecting rod is hinged to the support rod.

6. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: A second spring guide rod is horizontally fixed to the outer wall of the steel pipe. The reset spring is sleeved on the second spring guide rod. The length of the reset spring is greater than the length of the second spring guide rod. The end of the reset spring is fixed to the outer wall of the steel pipe.

7. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: The locking pin has a swing hole at its tail end, and the upper end of the connecting rod passes through the swing hole.

8. The equal-length adaptive variable stiffness vibration damping device according to claim 1, characterized in that: The upper surface of the first plate has an upper pull ring; the lower surface of the fourth plate has a lower pull ring.

Images